Screw threader and pointer.



F. N. TIL-TON.

SCREW THREADER AND POINTER. APPLICATION FILED AUG-1,1914. RENEWEDSEPT.2I, I917.

'5, 252, 6 3 o Patented Jan. 8 1918.

F. N. TILTON.

SCREW THREADER AND POINTER.

APPLICATION r1151) AUG-1. 1914. RENEWED sPT.21, 1911.

Patented Jan. 8, 1918.

6 SHEETS-SHEET 2.

52:11.4. 7/, PM Mfa/LW F. N. TiLTON.

SCREW THREADER'AND POINTER. APPLICATION FILED AUG- 1. mm.

RENEWED SEPT. 21, I917.

Patented Jan. 8, 1918.

6 SHEETS-SHEET 3.

x lad 42': 7

F. N. TlLTON.

SCREW THREADER AND POINTER.

APPLICATION FILED AUG-H1914. RENEWED SEPLZI, 1917.

Patented Jan. 8, 1918.

6 SHEETS-SHEET 4| .F. N. TILTON. SCREW THREADER AND POINTER. APPLICATIONFILED-AUG. 1. 1914. RENEWED SEPLZI, 19:7.

1,252,63Q; Patented Jan; 8, 1.918.

s SHEETSSHEET 5.

F. N. TILTON.

SCREW THREADER'AND POINTER. APPLICATION FILED AUG- 1. 1914. RENEWEDSEPT.2I, 1911.-

Patented Jan. 8, 1918.

6 SHEETSSHEET 6- STATES PATENT @FFICE.

ZIE IBJEII) NEWELL TILTON, F HARTFORD, CONNECTICUT.

' SCREW THREADER AND POINTER.

Specification of Letters Patent.

Fat-tented J an. 8, 1918.

i Applicationfilegi August 1,191 Serial No. 854,513. ,Renewed september21, 1917. Serial No. 192,628.

To all whom it may concern:

-Beit known that I, FRED N. TILT N, a -citizen, oftheUnited States,residing at -,Hartf0rd in the county of Hartfordand State ofConnecticut, have invented anew ,and useful Improvement. in ScrewThreaders and Pointers, of which the following is a specification.

This invention relates to the mechanism 111 a screw form ng machinewhlch controls the operation of the tool for cutting the jthreads uponthe blanks. As the invention is particularly applicable to the mechanismwhich affects the movements of the tool for threading and pointinggimletpointed wood screws it is illustrated and described herein asembodied in a wood screw machine.

In machines for threading and pointing gimlet-pointed wood screws theblanks are fed one at a time to a guide and driver and while rotated bythe driver are subjected to the action of a tool which is so fed as tocut the required threads, This tool is repeatedly fed along the blankfrom the shank to the point and returned, each time making apendsuponthelength of the screw a form or depth cutting cam whichthrough the ,form plate increases the depth of each cut until thethread. is completed; a return cam which acts, so. that the tool will bedrawn away from the blank during its return move- ,mentpand a holder camwhich acts so as to allow the tool to be held out while the blanks A,are being fed into the guide and engaged by the driver which causestheir rotation;

all of these parts being combined with the ,necessary actuating andconnecting mechanisms which cause them to automatically control themovements of the cuttingtool to effect-the desired result.

II he object .of this invention is to provide a machine of thischaracter with means whereby the tool, at each successive advance duringevery cycle of the machine, as it an proaches the tips of the blankswill not only cut deeper. but will be carried in toward the y axes oftheblanks so as to form the necessary gimlet points at the ends of thescrews, thus obviating thenecessity-of previously pointing the blanks inanother machine as has her tQfQ ae n. see idere ls ia o the successfulproduction of high-grade wood screws. i

This object is attained in a preferred manner by providing a pointingcam, and the necessary connections, which will slowly feed thecontrolling form in such manner that the tool each time it approachesthe end of a blank not only makes a deeper cut for forming the threadbut moves in so as to point the blank and form the desired thread on thepointed end.

As the blank feeding, rotating, guiding. and re easing mechanisms formno part of the present invention, and may be any of the types in commonuse, they are not illustrated'and described herein, only so much of awood screw machine being set forth as is necessary to a completecomprehension of the preferred embodiment of the invention. Flgure 1shows a front elevation of shows a side elevation of the form,,the formor depth cam which causes-the tool to cut deeper at each successivefeed, the holder am which allows the tool to be held out when the blanksare being fed into cutting position, and the levers which provide theconnections between these cams and the form. Fig. 7 is a section throughthe tool post on the plane indicated by the dotted 'line 77 on Fig. 1,showing a side elevation of the tool and its carrier, the tool post armand part of the form plate and arm. Fig. 8 I shows a plan of the formwith one of the form plates used for controlling the action of the tool.Fig. 9 shows a side View of the return cam, the form and the lever whichconnects these parts. Fig. 10 shows a plan of the form and the leverattached to the form arbor which is actuated. by the depth cam andholder cam.

The cutting tool 1 is adjustably fastened in a carrier 2 that is clampedon atool post 3. This post is loosely supported so that it may be turnedand also moved longitudinally in bearings in thestandards 4t and 5 hi h.extend ner l r fli s? t e b d f the tool actuating mechanism of the ma-'the machine illustrated. The tool post is 10. "post. The spring isfastened between moved in one direction for feeding thetool along fromthe shank to the point of the screw 7, by the lead cam 8 that isadjustably fastened to the front cam shaft 9, and the post is drawn inthe opposite direction by the spring 10 which has one end fastened tothe. standard 11, that extends upwardly from the bed, and which has itsotherend fastened .to an arm 12 that is clamped to the these parts sothat it not only holds the post back against the lead cam but tends todraw the arm in and turn the end of the cutting tool out from the screwblank. The lead cam is shaped and timed to advance the tool at such aspeed that it will cut a thread of the desired pitch on the screw blank.

Clamped on the tool post is an arm 13. The lower and inner end of thisarm is held against the form plate 14 by the pull of the spring 10 whichdraws back the tool post. This form platevaries in size and shapeaccording to the size and shape of the screw which is to be formed andits front edge is curved forwardly at one end so that as the tool postis moved by the cam for causing the tool to cut, the arm 13 near the endof its movement is forced out and the tool is turned in toward the axisof the blank forforming the point of the screw. The form plate isattached to an arm 15 which is clamped to the form arbor 16 that in themachine illustrated is loosely mounted in bearings in the standards 4, 5and 11;

Clamped on the form arbor is a rearwardly extending lever 17. This leverbears a spring finger '18 with a plate 19 which is adjusted to thedesired position by a screw 20. The plate 19 is held in contact with thedepth cam 21 by the pull of'a spring 22. The cam 21 is fastened on theback cam shaft 23. This cam is so shaped that through the lever 17 thearbor is turned and the form is swung in such manner that dur- "ingevery cycle of the machine, at each advance the tool will make a deepercut in the blank. F astened on the side of the depth cam 21 is theholder cam 24. This cam is adapted to engage the block 25, which is onone side of the lever 17, and hold the lever down with the form swungback so that the tool will be thrown out while during the operation ofthe machine ablank is, by any common feed mechanism, delivered intocutting position in the back guide 26 and is engaged by the driver 27 bymeans of which the blank is rotated, in the usual way in machines ofthis type.

'Adjustably fastened on the front cam. shaft 9 is the cam 28 which isadapted to engage the return cam lever 29 that is fastened to the formarbor 16. This cam is so timed that it rocks the lever, turns the arborand swings back the form so as to allow the tool to swing out away fromthe blank each 3 time it makes its return movement.

On the back cam shaft 23 is a cam 30 engaging with the face of which isthe end of longitudinally and carries the form side-- wlse so that ateach-successive advance of the tool the form arm 13 travels a littlefarther up on the curved end of the form plate.

As a result of this the tool not only at each advance makes a deeper cutbut at the end of each advance is caused to cut away the tip of theblank so as to form the desired point of the screw. 9

Power for rotating the shafts and cams is applied to the driving pulley35 which is on one end of the drive shaft 36 that extends across themachine and at the other end has a drive'pinion 37. The drive pinionmeshes with an intermediate gear 38 which with its attached pinion 39 ismounted on a bracket40 that is adjustably fastened to the outer face ofthe standard 11. The pinion 39 engages with the gear 41 that is fastenedon the front cam shaft 9. Attached to this gear is a pinion 42 whichmeshes with a sec ond intermediate gear 43 that with its attached pinion44 is mounted on a bracket'45 that is adjustably fastened to the outerface of the standard 11. The pinion 44 engages with a gear 46 that isfastened to the end of the back cam shaft 23. 7

By means'of the addition to'the screw machines in common use of thesimple pointing cam and lever for moving the form arbor as abovedescribed, the form, which controls the depth at which the tool cutsinto the blank,--which permits the tool to return freely after eachcut,and which permits the tool to be held out while the a spring forreturning the tool, a form for controlling the movements of the tool, a

depth cam actuating the form so as to 'regulate thedepth of the toolcut, a pointing cam actuatmg the form so as to cause the tool to pointthe blank, and a return cam actuating the form so as to allow the toolto withdraw from the blank when it is returned.

2. The combination in a screw machine of a tool, a lead cam foradvancing the tool, a spring for returning the tool, a form forcontrolling the movements of the tool, a cam actuating the form forregulating the depth of the tool cut, a cam actuating the form forcausing the tool to cut the point of the blank, a cam actuating the formfor causing the tool to be Withdrawn from the blank during its returnmovement, and a cam actuating the form for holding the tool out Whilethe blank is being located in position to be cut.

3. The combination in a screw machine of a tool, a cam for advancing thetool, an oscillatory and reciprocatory form for controlling the positionof the point of the tool, a cam for swinging the form so that eachsuccessive cut of the tool Will be deeper than the preceding cut, and acam for feeding the form longitudinally so that near the end of eachadvance the tool will cut deeper than at the same locality during thepreceding cut for threading and pointing a screw.

4. The combination in a screw machine of a tool, a lead cam foradvancing the tool, a spring for returning the tool and holding it awayfrom the blank, an oscillatory and reciprocatory form for turning thepoint of the tool toward the blank, a cam for swinging the form so as toincrease the depth of the successive cuts, and a cam for reciprocatingthe form so as to still more increase the depth of the successive cutsnear the end of each advance movement of the tool.

5. The combination in a screw machine of a tool, a form for controllingthe cutting action of the tool, and two independent cams arranged toactuate the form, one of said cams feeding the form transversely so asto regularly increase the depth of each tool cut, and the other of saidcams feeding the form longitudinally so as to still further increase thedepth of each tool cut near the point of the blank.

6. The combination in a screw machine, of an oscillatory andreciprocatory form, a spring cam and lever for oscillating the form, anda spring, cam and lever for reciprocating the form.

7. The combination in a screw machine of an oscillatory andreciprocatory form, means for oscillating the form, and means forreciprocating the form, said form oscillating and form reciprocatingmeans being separate and acting independently of each other.

FRED NEWELL TILTON.

W'itnesses:

J AMES F. STOREY, Gnaon GAULT.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. C."

